i) Field of the Invention
The present invention relates to connection between capacitor elements and external terminals that are in sealing members sealing openings of outer packaging members of capacitor elements, and relates to capacitors that use laser welding for their connection, for example, capacitors such as electrolytic capacitors and electric double layer capacitors, and methods for manufacturing such capacitors.
ii) Description of the Related Art
It is necessary for capacitor elements and external terminals to be electrically connected in electric double layer capacitors or electrolytic capacitors. Such electrical connection provides courses for reducing internal resistance of elements and contact resistance of connecting portions.
Concerning such electrical connection, the following are known: to provide current collector terminals for the end-faces of elements (for example, Japanese Patent Application Laid-Open Publication No. H11-219857); to provide an anode current collector plate for one end-face of each wound element, and a cathode current collector plate for the other end-face (for example, Japanese Patent Application Laid-Open Publication No. 2001-068379); to provide a current collector plate so that the current collector plate covers current collector foil which is bare over an end-face of each wound element, and to connect the current collector plates and the current collector foil by welding (for example. Japanese Patent Application Laid-Open Publication No. 2007-335156); and to use current collector plates for connection between encapsulating cases and elements and for connection with external terminals (for example, Japanese Patent Application Laid-Open Publication No. 2010-093178).
Multi-layered capacitor elements, which provide connection terminals for their element end faces, are also known (for example, Japanese Patent Application Laid-Open Publication No. H6-275476).